This invention pertains to systems for enabling the communication of digital media signals and data between a media source device, such as a musical instrument, and electronic components needed to control and re-produce sounds generated by that source device. More specifically, this invention relates to a system and method that facilitates the interconnection of one or more diverse musical instruments and related audio components on a universal network for purposes of communication of audio signals and signals to identify and control the devices.
The generation, transmission, amplification and control of audio and other media signals and devices involve diverse yet interrelated technologies that are changing rapidly. The development and implementation of high bandwidth digital communication technologies and distribution systems is significantly affecting all media industries, from book publishing to television/video broadcasting. Products, systems, and services that affect the sense of sight or sound are converging in the use of common technologies and distribution pipelines. This has a profound effect, not only on the nature of the products that are produced, but on the sales channels and the methods of producing content for those products.
Current examples of the convergence of audio and digital technologies are the arrival and consumer acceptance of the MPEG-3 digital music format, the inexpensive recordable CD (e.g., the xe2x80x9cMiniDiscxe2x80x9d), and the high bandwidth Internet. However, the markets for technology-driven products are not served by implementation of multiple technical standards. Typically, a new technology begins in its early phase with multiple standards, which in many cases are vigorously debated and disputed among various advocates for the different standards. In most technology-driven industries that prosper, a single standard historically is universally adopted by members of that industry.
Similarly, there is a need for a universally accepted standard for digital communication of audio and video content. Because of the overwhelming acceptance of the Internet and its TCP/IP protocol, coupled with a substantial pre-existing infrastructure of network hardware, software, and know-how, a universal standard for digital audio/video communication and control should revolve around this well-known TCP/IP and Internet technology.
The weakness of the existing audio hardware market is in its application of digital electronic technologies. Today""s musicians can record and process multiple-tracks of high quality sound on their computers but are forced to plug into boxes with 1950""s era analog circuits. For example, the original challenge in the guitar musical instrument industry was to make the guitar louder. The circuits of the day distorted the sound of the instrument, but did accomplish their task. With time, these distortions became desirable tones, and became the basis of competition.
Guitar players and other musicians are very interested in sound modification. Digital technology allows musicians to create an infinite variety of sound modifications and enhancements. Musicians in small clubs typically have a veritable arsenal of pedal boxes, reverb effects, wires, guitars and the like. They generally have a rack of effects boxes and an antiquated amplifier positioned somewhere where the sound distribution is generally not optimal because the amplifier is essentially a point source. Because of this lack of accurate sound placement, the sound technician is constantly struggling to integrate the guitar player into the overall sound spectrum, so as to please the rest of the band as well as the audience who would love to hear the entire ensemble. Current solutions for this issue include positioning a microphone in front of a speaker and then mixing the audio from the microphone with the house sound.
Technology has made some progress along a digital audio path. For example, there are prior art guitar processors and digital amplifiers that use digital signal processing (DSP) to allow a single guitar to emulate a variety of different guitar sounds, amplifier types, and other sound modifications such as reverb and delay. To achieve the same variety of sounds and variations without using DSP technology, a musician would have to buy several guitars, several different amplifiers, and at least one, if not more than one, accessory electronic box.
All existing instruments, if they use a transducer of any kind, output the sound information as an analog signal. This analog signal varies in output level and impedance, is subject to capacitance and other environmental distortions, and can be subject to ground loops and other kinds of electronic noise. After being degraded in such fashion by the environment, the analog signal is often digitized at some point, with the digitized signal including the noise component. Although existing digital audio technologies show promise, it is clear that the audio equipment and musical instrument industries would benefit from a system and method where all audio signals are digital at inception or at the earliest possible point in the signal chain.
At present, there are multiple digital interconnection specifications, including AES/EBU, S/PDIF, the ADAT xe2x80x9cLight Pipexe2x80x9d and IEEE 1394 xe2x80x9cFirewirexe2x80x9d. However, none of these standards or specifications is physically appropriate for the unique requirements of live music performance. In addition, clocking, synchronization, and jitter/latency management are large problems with many of these existing digital options.
Different segments of the music market have experimented in digital audio. Some segments have completely embraced it, but there is no appropriate scalable standard. Clearly, digital components exist, but these are designed to function as stand alone digital devices. Correspondingly, many manufacturers have chosen to make their small portion of the product world digital but rely mainly on traditional analog I/O to connect to the rest of the world. This may solve the local problem for the specific product in question, but does little to resolve the greater system-oriented issues that arise as the number of interconnected devices grows. In addition, the small sound degradation caused by an analog-to-digital and digital-to-analog transformation in each xe2x80x9cboxxe2x80x9d combines to produce non-optimal sound quality. Finally, the cost, power and size inefficiency related to having each component in a chain converting back and forth to digital begs for a universal, end-to-end digital solution.
Another basic yet important part of the problem is that live musicians need a single cable that is long, locally repairable, and simple to install and use. In addition, it is highly desirable to support multiple audio channels on a single cable, as setups often scale out of control with current multiple cable solutions. Providing low current, DC power through the cable for the active circuits used in digital instruments would be preferable to the use of batteries which many conventional instruments depend on.
Based on the technology trends and patterns that have already been established, a digital guitar will emerge with the transducers (pick-ups) feeding a high bandwidth digital signal. This advance will remove many detrimental aspects of the analog technology it will replace, including noise, inconsistent tonal response from time to time, and loss of fidelity with a need for subsequent signal processing. The introduction of digital technology from the instrument will allow the entire signal path and the equipment associated with the signal path to be digital. Unfortunately, there is no system available to interconnect multiple musical instruments and associated audio components so that they can communicate with each other and be controlled entirely in the digital domain, using a universal interface and communications protocol.
In summary, despite dramatic advances in technology, real-time high-fidelity digital audio has yet to permeate both production and live performance. Increasing demand has motivated little effort to apply modern network technology towards producing superior quality real-time audio devices, at low prices. A small number of isolated digital systems do exist but they rely on archaic analog interfaces to connect with other devices. An increasing demand for more interconnected devices has resulted in diminished sound quality in these systems, caused by repeated analog-to-digital and digital-to-analog conversions. Additionally, this conversion requires capability that often results in prohibitive size and power requirements.
Many of the existing systems are difficult to install, lack flexible reconfiguration capabilities, and do not take advantage of intuitive user-friendly hardware and software interfaces. Existing digital interconnection specifications do not satisfy the unique requirements of live audio performances, particularly in the areas of clocking, distance synchronization, and jitter/latency management.
Thus, there remains a compelling need in the audio industry for an open architecture digital interconnect that would allow audio products from different vendors (musical instruments, processors, amplifiers, recording and mixing devices, etc.), to seamlessly communicate.
A primary object of the present invention is to adapt digital technology invented for computer network products to audio equipment, and to develop an interconnect that is reliable over long distances, locally repairable, trivial to install, and simple to use.
Another object of the invention is to provide a musical device interconnect and communications system and method that is capable of supporting multiple audio channels of advanced fidelity audio.
A further object of the invention is to implement a system that enables installations to scale beyond the capacity of existing multiple cable solutions and meet the requirements of permanent installations such as live venues and recording studios.
Yet another object of the present invention is to provide power for digital instruments thereby eliminating the need for batteries.
These and other objects must be accomplished by augmenting and not diminishing the acoustic, electric, or physical characteristics of musical instruments.
Accordingly, the system and method of the present invention provides the audio industry with an Open Architecture digital interconnect that allows audio products from different vendors (musical instruments, processors, amplifiers, recording and mixing devices, etc.), to seamlessly communicate. For convenience, the system of the present invention will sometimes be referred herein as the Media Accelerated Global Information Carrier (or MAGIC). MAGIC(trademark) is a trademark of Gibson Guitar Corp., the assignee of the present invention. MAGIC overcomes the limitations of point-to-point solutions by providing inexpensive yet seamless enhanced digital sonic fidelity. The MAGIC system provides the ability to create audio networks appropriate for use in a wide variety of environments ranging from professional audio to home music installations. A MAGIC system provides a single cable solution that is trivial to install, requires little or no maintenance, and offers a data link layer that supports a simple yet sophisticated protocol, capable of offering a superior user experience.
A MAGIC system provides up to 32 channels of 32-bit-bi-directional high-fidelity audio with sample rates up to 192 kHz. Data and control can be transported 30 to 30,000 times faster than MIDI. Added cable features include power for instruments, automatic clocking, and network synchronization.
The system is scalable to provide, for example, 32 channels of 48 kHz, 24 bit audio, 16 channels of 96 kHz, 24 bit audio, or 8 channels of 192 kHz, 24 or 32 bit audio, with an embedded command layer.
The system of this invention includes the MAGIC data link, a high-speed network connection for communication of digital audio data between two MAGIC devices. The system and method of the invention further includes definitions and description of the characteristics of individual MAGIC devices as well as MAGIC system configuration and control protocols.
The MAGIC data link is a high-speed connection transmitting full-duplex digital audio signals, control signals, and device enumeration and/or individual user data between two interconnected MAGIC devices. Self-clocking data are grouped into frames that are continuously transmitted between MAGIC devices at the current sample rate.
Flexible packing of digital audio data within a frame allows a tradeoff between sample rate and channel capacity to optimize the fit and interface for MAGIC devices having diverse characteristics. A Control data field provides for MAGIC system configuration, device identification, control, and status. User data fields are provided for transmitting non-audio data between MAGIC devices.
A MAGIC system will typically include multiple xe2x80x9cMAGIC devicesxe2x80x9d. A MAGIC device is any device equipped with a MAGIC Link that allows it to exchange bi-directional, fixed-length data and control, at a determined network sample rate. A MAGIC device can be an instrument having a sound transducer such as a guitar, microphone, or speaker. A MAGIC device can also be an intelligent device that provides connections and power for multiple MAGIC devices, and is capable of, and responsible for, configuring the MAGIC system. A MAGIC device controller may also include upstream and downstream connections (in hub and spoke or daisy chain configurations) to other devices for increased instrument connectivity.
Data link electronics and associated cabling and connectors are designed for reliable use in harsh environments. xe2x80x9cHot-pluggingxe2x80x9d of MAGIC devices is supported by the system.
Accordingly, a Universal Digital Media Communications and Control System is provided that includes the following novel features:
(1) The Control data for each device includes a xe2x80x9cFriendly namingxe2x80x9d scheme using a Device ID so that: (a) there is an automatic configuration by, and synchronization to, the system by the identifying device; (b) the use of a xe2x80x9cFriendly namexe2x80x9d allows the user to name his device on the system; (c) the xe2x80x9cdevice namexe2x80x9d resides in the device, not in a data base; and (d) the device ID is available when the device is plugged into a xe2x80x98foreignxe2x80x99 MAGIC system.
(2) A bi-directional device interface is provided that adds xe2x80x9cresponsexe2x80x9d to the existing instrument stimulus to create a full duplex instrument that is able to display and react to other devices in the system.
(3) The system topology allows for nodal connection of resources so that instruments and control devices plug in to create the desired system complexity and allowing for simple system enhancement by plugging in a new device with the desired features.
(4) The system implements dynamic resource allocation, including: (a) routing of audio and control signals xe2x80x9con the flyxe2x80x9d; (b) audio nodes can be xe2x80x98movedxe2x80x99 at will; and (c) special effects devices can be shared with out physically moving or connecting them.
(5) Logical connections are made to the system so that a device can be physically connected into the system through any available connector, e.g., a guitar does not have to be directly plugged into the guitar amplifier.
(6) The system has a multi-layered protocol that supports many different physical transport media and allows for simple expansion of both the number of audio channels and the data bandwidth.
(7) There can be a familiar looking (to the user) point to point connection of devices, or a xe2x80x9cstarxe2x80x9d network (analogous to a xe2x80x9cbreakout boxxe2x80x9d) configuration for multiple devices, thereby simplifying the user experience.
(8) Phantom power for instrument electronics is delivered over the MAGIC data link.
(9) The system can take advantage of conventional network hardware, e.g., one embodiment of a MAGIC system is implemented over a 100-megabit Ethernet physical layer using standard Category 5 (CAT5) cable and RJ-45 connectors.
Thus, the present invention is the first low-cost digital interconnection system based on a universal standard that is appropriate for use in the live, professional, studio and home music performance environments. The MAGIC technology of this system can be quickly adapted for use in musical instruments, processors, amplifiers, recording devices, and mixing devices.
The system of this invention overcomes the limitations and performance liabilities inherent in current xe2x80x9cpoint solutionxe2x80x9d digital interfaces and creates a completely digital system that offers enhanced sonic fidelity, simplified setup and usage while providing new levels of control and reliability.
MAGIC enables musical instruments and supporting devices such as amplifiers, mixers, and effect boxes from different vendors to digitally inter-operate in an open-architecture infrastructure. MAGIC creates a single-cable system with 32 audio channels both to and from the instrument and also includes high-resolution control and data channels.
This modular, scalable system overcomes the limits and liabilities inherent in current xe2x80x9cpoint solutionxe2x80x9d digital interfaces. MAGIC creates a completely digital system that offers enhanced sonic fidelity, simplified setup and usage while providing new levels of control and reliability. The MAGIC protocol is independent of the physical layer itself. MAGIC can be delivered over any deterministic wire-, wireless- or optical-based digital transport mechanism. The MAGIC system and method of this invention is unique in that it takes the non-realtime environment of Ethernet, and transforms it into a synchronous, real-time audio transport. This is achieved by a set topology rules that determine that there is always a single master clock, and signaling at a fixed rate. This sync is propagated across the network, assuring all services are in phase.